U.S. patent number 9,427,838 [Application Number 14/552,993] was granted by the patent office on 2016-08-30 for head tool changer for use with deposition-based digital manufacturing systems.
This patent grant is currently assigned to Stratasys, Inc.. The grantee listed for this patent is Stratasys, Inc.. Invention is credited to David G. Bocek, Michael D. Bosveld, James W. Comb, Joseph E. Labossiere, Max Peters.
United States Patent |
9,427,838 |
Comb , et al. |
August 30, 2016 |
Head tool changer for use with deposition-based digital
manufacturing systems
Abstract
A head tool changer for use with a deposition-based digital
manufacturing system, the head tool changer comprising a tooling
unit configured to retain a deposition head, a grip unit configured
to engage with tooling unit and to relay electrical power to the
tooling unit, and a master unit operably mounted to a gantry and
configured to engage with the tooling unit and to relay electrical
power to the tooling unit.
Inventors: |
Comb; James W. (Hamel, MN),
Labossiere; Joseph E. (Rogers, MN), Bosveld; Michael D.
(Bloomington, MN), Bocek; David G. (Plymouth, MN),
Peters; Max (Minnetonka, MN) |
Applicant: |
Name |
City |
State |
Country |
Type |
Stratasys, Inc. |
Eden Prairie |
MN |
US |
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Assignee: |
Stratasys, Inc. (Eden Prairie,
MN)
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Family
ID: |
52117214 |
Appl.
No.: |
14/552,993 |
Filed: |
November 25, 2014 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20150137401 A1 |
May 21, 2015 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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13074523 |
Mar 29, 2011 |
8926484 |
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61318430 |
Mar 29, 2010 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B29C
64/209 (20170801); B23Q 3/155 (20130101); Y10T
483/12 (20150115); Y10T 483/136 (20150115); B29C
64/118 (20170801); B33Y 30/00 (20141201); Y10T
483/10 (20150115); Y10S 483/901 (20130101); Y10T
483/17 (20150115); B29C 64/106 (20170801) |
Current International
Class: |
B23Q
3/155 (20060101); B29C 67/00 (20060101); B33Y
10/00 (20150101); B33Y 30/00 (20150101) |
Field of
Search: |
;700/118,119,120
;483/4,7,10,11,16,901,1 ;425/162,166,186,190,192R ;264/308 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Cadugan; Erica E
Assistant Examiner: Vitale; Michael
Attorney, Agent or Firm: Westman, Champlin & Koehler,
P.A.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION(S)
This application claims priority to U.S. Provisional Patent
Application No. 61/318,430, filed on Mar. 29, 2010, and entitled
"HEAD TOOL CHANGER FOR USE WITH DEPOSITION-BASED DIGITAL
MANUFACTURING SYSTEMS", the disclosure of which is incorporated by
reference in its entirety.
Claims
The invention claimed is:
1. A method for building a three-dimensional model with a
deposition-based digital manufacturing system, the method
comprising: engaging a tooling unit with a tool rest assembly,
wherein the tooling unit retains a deposition head; relaying
electrical power through the tool rest assembly and the tooling
unit to the retained deposition head while the tooling unit is
engaged with the tool rest assembly; disengaging the tooling unit
from the tool rest assembly; moving the tool rest assembly away
from the tooling unit; engaging the tooling unit with a master unit
that is operably mounted to a gantry of the deposition-based
digital manufacturing system; relaying electrical power through the
master unit and the tooling unit to the retained deposition head
while the tooling unit is engaged with the master unit; moving the
master unit and the retained deposition head with the gantry;
feeding a consumable material through the retained deposition head
with the electrical power relayed through the master unit and the
tooling unit; and depositing the fed consumable material from the
retained deposition head while moving the master unit to build at
least a portion of the three-dimensional model using a layer-based
additive technique.
2. The method of claim 1, wherein the deposition-based digital
manufacturing system comprises a controller, and wherein the method
further comprises relaying control signals from the controller
through the master unit and the tooling unit to the retained
deposition head while the tooling unit is engaged with the master
unit.
3. The method of claim 1, wherein the tool rest assembly comprises
a turret configured to retain a plurality of deposition heads.
4. The method of claim 1, and further comprising heating up the
deposition head with the electrical power relayed through the tool
rest assembly and the tooling unit.
5. The method of claim 1, and further comprising: engaging the
tooling unit with a grip unit operably connected to an actuator
assembly; disengaging the tooling unit from the tool rest assembly;
and moving the actuator assembly to position the tooling unit
proximate to the master unit.
6. The method of claim 1, and further comprising: drawing a vacuum
through a purge receptacle; and purging the deposition head into
the purge receptacle.
7. The method of claim 1, and further comprising: disengaging the
tooling unit from the master unit; re-engaging the tooling unit
with the tool rest assembly; and relaying electrical power through
the tool rest assembly and the re-engaged tooling unit to the
retained deposition head while the tooling unit is re-engaged with
the tool rest assembly.
8. The method of claim 7, wherein the tooling unit is a first
tooling unit and the deposition head is a first deposition head,
and wherein the method further comprises: engaging a second tooling
unit with the tool rest assembly, wherein the second tooling unit
retains a second deposition head; relaying electrical power through
the tool rest assembly and the second tooling unit to the retained
second deposition head while the second tooling unit is engaged
with the tool rest assembly; after disengaging the first tooling
unit from the master unit, engaging the second tooling unit with
the master unit; and relaying electrical power through the master
unit and the second tooling unit to the retained second deposition
head while the second tooling unit is engaged with the master
unit.
9. The method of claim 1, wherein the deposition head comprises a
single extrusion line.
10. A method for building a three-dimensional model with a
deposition-based digital manufacturing system, the method
comprising: providing a tooling unit having a first electrical
contact, a second electrical contact, a first locking mechanism,
and a second locking mechanism, and which retains a deposition
head; engaging the first electrical contact and the first locking
mechanism of the tooling unit to a tool rest assembly; relaying
electrical power through the tool rest assembly, the first
electrical contact and the tooling unit to the retained deposition
head while the tooling unit is engaged with the tool rest assembly;
engaging the second electrical contact and the second locking
mechanism of the tooling unit with a grip unit operably mounted to
an actuator assembly; relaying electrical power through the grip
unit, the second electrical contract, and the tooling unit to the
retained deposition head while the tooling unit is engaged with the
grip unit; and loading the retained deposition head into position
on a gantry of the deposition-based digital manufacturing system
using the actuator assembly for building at least a portion of the
three-dimensional model using a layer-based additive technique.
11. The method of claim 10, wherein the deposition-based digital
manufacturing system comprises a controller, and wherein the method
further comprises relaying control signals from the controller
through the grip unit and the tooling unit to the retained
deposition head while the tooling unit is engaged with the grip
unit.
12. The method of claim 10, and further comprising heating up the
deposition head with the electrical power relayed through the tool
rest assembly and the tooling unit.
13. The method of claim 10, and further comprising: moving the
tooling unit with the retained deposition head back to the tool
rest assembly at least in part with the actuator assembly;
re-engaging the tooling unit with the tool rest assembly;
disengaging the tooling unit from the grip unit, and relaying
electrical power through the tool rest assembly and the re-engaged
tooling unit to the retained deposition head while the tooling unit
is re-engaged with the tool rest assembly.
14. The method of claim 10, and further comprising: drawing a
vacuum through a purge receptacle; and purging the deposition head
into the purge receptacle.
15. A method for building a three-dimensional model with a
deposition-based digital manufacturing system, the method
comprising: engaging a tooling unit with a tool rest assembly,
wherein the tooling unit retains a deposition head; relaying
electrical power through the tool rest assembly and the tooling
unit to the retained deposition head while the tooling unit is
engaged with the tool rest assembly; engaging the tooling unit with
a grip unit operably mounted to an actuator assembly; disengaging
the tooling unit from the tool rest assembly after engaging the
grip unit; moving the tool rest assembly away from the actuator
assembly; engaging the tooling unit with a master unit that is
operably mounted to a gantry of the deposition-based digital
manufacturing system; relaying electrical power through the master
unit and the tooling unit to the retained deposition head while the
tooling unit is engaged with the master unit; disengaging the
tooling unit from the grip unit after engaging the master unit; and
building at least a portion of the three-dimensional model using a
layer-based additive technique with the deposition head while the
tooling unit is engaged with the master unit.
16. The method of claim 15, wherein the deposition-based digital
manufacturing system comprises a controller, and wherein the method
further comprises relaying control signals from the controller
through the master unit and the tooling unit to the retained
deposition head while the tooling unit is engaged with the master
unit.
17. The method of claim 15, wherein the tool rest assembly
comprises a turret configured to retain a plurality of deposition
heads.
18. The method of claim 15, and further comprising heating up the
deposition head with the electrical power relayed through the tool
rest assembly and the tooling unit.
19. The method of claim 15, and further comprising: re-engaging the
grip unit with the tooling unit; disengaging the tooling unit from
the master unit after engaging the grip unit; moving the tooling
unit with the retained deposition head back to the tool rest
assembly at least in part with the actuator assembly; re-engaging
the tooling unit with the tool rest assembly; and disengaging the
tooling unit from the grip unit.
20. The method of claim 15, and further comprising: drawing a
vacuum through a purge receptacle; and purging the deposition head
into the purge receptacle.
Description
BACKGROUND
The present disclosure relates to deposition-based digital
manufacturing systems for building three-dimensional (3D) models
with layer-based additive techniques. In particular, the present
invention relates to devices for loading multiple deposition heads
to deposition-based digital manufacturing systems, such as
extrusion-based digital manufacturing systems.
An extrusion-based digital manufacturing system (e.g., fused
deposition modeling systems developed by Stratasys, Inc., Eden
Prairie, Minn.) is used to build a 3D model from a digital
representation of the 3D model in a layer-by-layer manner by
extruding a flowable consumable modeling material. The modeling
material is extruded through an extrusion tip carried by an
extrusion head, and is deposited as a sequence of roads on a
substrate in an x-y plane. The extruded modeling material fuses to
previously deposited modeling material, and solidifies upon a drop
in temperature. The position of the extrusion head relative to the
substrate is then incremented along a z-axis (perpendicular to the
x-y plane), and the process is then repeated to form a 3D model
resembling the digital representation.
Movement of the extrusion head with respect to the substrate is
performed under computer control, in accordance with build data
that represents the 3D model. The build data is obtained by
initially slicing the digital representation of the 3D model into
multiple horizontally sliced layers. Then, for each sliced layer,
the host computer generates a build path for depositing roads of
modeling material to form the 3D model.
In fabricating 3D models by depositing layers of a modeling
material, supporting layers or structures are typically built
underneath overhanging portions or in cavities of objects under
construction, which are not supported by the modeling material
itself. A support structure may be built utilizing the same
deposition techniques by which the modeling material is deposited.
The host computer generates additional geometry acting as a support
structure for the overhanging or free-space segments of the 3D
model being formed. Consumable support material is then deposited
from a second nozzle pursuant to the generated geometry during the
build process. The support material adheres to the modeling
material during fabrication, and is removable from the completed 3D
model when the build process is complete.
SUMMARY
An aspect of the present disclosure is directed to a head tool
changer for use with a deposition-based digital manufacturing
system. The head tool changer includes a tooling unit configured to
retain a deposition head of the system, and an actuator assembly
operably mounted to the system, where at least a portion of the
actuator assembly is configured to move along an axis. The head
tool changer also includes a grip unit secured to the actuator
assembly and configured to engage with tooling unit and to relay
electrical power to the tooling unit, and a master unit operably
mounted to a gantry of the system, where the master unit is
configured to engage with the tooling unit and to relay electrical
power to the tooling unit.
Another aspect of the present disclosure is directed to a head tool
changer for use with a deposition-based digital manufacturing
system, where the head tool changer includes a plurality of tooling
units, each being configured to retain a deposition head of the
system, and a plurality of actuator assemblies operably mounted to
the system, where at least a portion of each of the plurality of
actuator assemblies is configured to move along an axis. The head
tool changer also includes a plurality of grip units secured to the
plurality of actuator assemblies, where each grip unit is
configured to engage with one of the tooling units, and a master
unit operably mounted to a gantry of the system, where the tooling
units are configured to interchangeably engage with the master
unit.
Another aspect of the present disclosure is directed to a method
for changing deposition heads in a deposition-based digital
manufacturing system. The method includes providing a grip unit
engaged with a tooling unit, where the tooling unit is secured to
one of the deposition heads, relaying electrical power through the
grip unit and the tooling unit to the secured deposition head, and
engaging the tooling unit with a master unit that is operably
mounted to a gantry of the system. The method also includes cutting
the relay of the electrical power through the grip unit and the
tooling unit, relaying electrical power through the master unit and
the tooling unit to the secured deposition head while the tooling
unit is engaged with the master unit, and disengaging the grip unit
from the tooling unit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a deposition-based digital manufacturing
system in use with a head tool changer of the present
disclosure.
FIGS. 2A-2P are schematic illustrations of a process for
interchangeably loading deposition heads to a gantry of the digital
manufacturing system with the use of the head tool changer.
FIG. 3 is a schematic illustration of the engagements between a
grip unit, a tooling unit, and a master unit of the head tool
changer.
FIG. 4 is a front perspective view of a tool rest assembly and
actuator assemblies of the head tool changer.
FIG. 5 is a rear perspective view of the tool rest assembly and the
actuator assemblies of the head tool changer.
FIG. 6 is a first side perspective view of one of the actuator
assemblies and grip units retaining a tooling unit and a deposition
head.
FIG. 7 is a second side perspective view of the actuator assembly
and the grip unit retaining the tooling unit and the deposition
head, which is taken from an opposing side from the view shown in
FIG. 6.
FIG. 8 is a top perspective view of the tooling unit and the
deposition head engaged with the master unit.
FIG. 9A is a top perspective view of the grip unit.
FIG. 9B is a bottom perspective view of the grip unit.
FIG. 10A is a top perspective view of the tooling unit.
FIG. 10B is a bottom perspective view of the tooling unit.
FIG. 11A is a top perspective view of the master unit.
FIG. 11B is a bottom perspective view of the master unit.
FIG. 12A is a top perspective view of the grip unit, the tooling
unit, and the master unit.
FIG. 12B is a bottom perspective view of the grip unit, the tooling
unit, and the master unit.
FIG. 13 is a rear perspective view of a portion of the tool rest
assembly in use with a deposition head retained by the actuator
assembly.
FIG. 14 is a schematic illustration of an alternative head tool
changer of the present disclosure.
DETAILED DESCRIPTION
The present disclosure is directed to a head tool changer that may
be mounted to a direct digital manufacturing system, such as a
deposition-based digital manufacturing system. The head tool
changer is configured to interchangeably load multiple deposition
heads to a gantry of the digital manufacturing system, where the
multiple deposition heads may be used to build 3D models and
support structures using a layer-based additive technique. As
discussed below, this allows 3D models and support structures to be
built with multiple materials, may reduce transition times when
switching materials, and may allow operators to service and repair
idle deposition heads while 3D model and support structures are
being built.
FIG. 1 is a front view of system 10 in use with head tool changer
12, where system 10 is a deposition-based digital manufacturing
system and head tool changer 12 is an example of a suitable head
tool changer of the present disclosure. Suitable deposition-based
digital manufacturing systems for system 10 include extrusion-based
systems and/or jetting systems, each of which may build 3D models
and corresponding support structures using a layered-based additive
technique. Suitable extrusion-based systems for system 10 include
fused deposition modeling systems developed by Stratasys, Inc.,
Eden Prairie, Minn., such as those disclosed in Comb et al., U.S.
Pat. No. 5,939,008; Swanson et al., U.S. Pat. Nos. 6,722,872 and
6,776,602; and Comb et al., U.S. Publication Nos. 2010/0100224 and
2010/0100222; and those commercially available under the trade
designation "FORTUS" from Stratasys, Inc., Eden Prairie, Minn.
System 10 includes build chamber 14, platform assembly 16, and
gantry 18, and bays 19a-19d, where build chamber 14 is an enclosed
environment that contains platform assembly 16 and a portion of
gantry 18. During a build operation, build chamber 14 is desirably
heated to reduce the rate at which the modeling and support
materials solidify after being extruded and deposited.
Platform assembly 16 is a receiving platform on which a 3D model
and corresponding support structure (not shown) are built, and
desirably moves along a vertical z-axis based on signals provided
from system controller 20. Examples of suitable platforms for
platform assembly 16 include those disclosed in Comb et al., U.S.
Publication No. 2010/0100222. System controller 20 is one or more
computer-operated controllers for operating system 10, and may be
located internally or externally to system 10.
Gantry 18 is a guide rail system that is desirably configured to
move a deposition head of multiple interchangeable deposition heads
22a-22d in a horizontal x-y plane within build chamber 14 based on
signals provided from system controller 20. The horizontal x-y
plane is a plane defined by an x-axis and a y-axis, where the
x-axis, the y-axis, and the z-axis are orthogonal to each other. In
an alternative embodiment, platform assembly 16 may be configured
to move along two axes within build chamber 14 (e.g., x-z plane or
the y-z plane), and the loaded deposition head may be configured to
move along a single horizontal axis (e.g., the x-axis or the
y-axis). Other similar arrangements may also be used such that one
or both of platform assembly 16 and the loaded deposition head are
moveable relative to each other.
In the shown embodiment, gantry 18 is configured to retain a single
deposition head. As such, head tool changer 12 may only load one of
deposition heads 22a-22d to gantry 18 at any given time. Of course,
when system 10 is not operating, all four deposition heads 22a-22d
can be removed from gantry 18. In alternative embodiments, gantry
18 may be configured to retain multiple deposition heads, such as
disclosed in Swanson et al., U.S. patent application Ser. No.
12/180,140.
Suitable deposition heads for deposition heads 22a-22d may include
a variety of different deposition-based devices, such as extrusion
heads, jetting heads, and combinations thereof. Examples of
suitable extrusion heads for each of deposition heads 22a-22d
include those disclosed in LaBossiere, et al., U.S. Patent
Application Publication Nos. 2007/0003656 and 2007/00228590; and
Leavitt, U.S. Patent Application Publication No. 2009/0035405.
Alternatively, deposition heads 22a-22d may each include one or
more two-stage pump assemblies, such as those disclosed in
Batchelder et al., U.S. Pat. No. 5,764,521; and Skubic et al., U.S.
Patent Application Publication No. 2008/0213419. As discussed
below, however, because head tool changer 12 allows deposition
heads 22a-22d to be interchangeably loaded to gantry 18, deposition
heads 22a-22d each desirably only includes a single deposition line
(e.g., a single extrusion line) rather than a pair of deposition
lines that are toggled back and forth between active and non-active
states.
Deposition heads 22a-22d desirably receive consumable materials
(e.g., modeling and support materials) from one or more supply
sources (not shown) loaded to bays 19. In some embodiments, the
consumable materials may be provided to system 10 as filaments. In
these embodiments, suitable supply sources include spools and/or
spooled containers, such as those disclosed in Swanson et al., U.S.
Pat. No. 6,923,634; Comb et al., U.S. Pat. No. 7,122,246; and
Taatjes et al, U.S. Publication Nos. 2010/0096489 and 2010/0096485.
Deposition heads 22a-22d may each also receive consumable materials
from two or more spools or spooled containers loaded into bays 19
to provide for a continuous operation, as disclosed in Swanson et
al., U.S. Pat. No. 6,923,634.
In the shown embodiment, head tool changer 12 is secured to a top
section of system 10, and includes housing 24, tool rest assembly
26, and actuator assemblies 28a-28d. Housing 24 is an exterior
housing for protecting the components of head tool changer 12. In
one embodiment, housing 24 may encase tool rest assembly 26 and
actuator assemblies 28a-28d, and may include a service door (not
shown) to allow an operator of system 10 to access components
retained within housing 24 (e.g., deposition heads 22a-22d). Tool
rest assembly 26 is a component that allows one or more of
deposition heads 22a-22d to be initialized (e.g., warmed up and
purged) prior to use. Actuator assemblies 28a-28d are extendable
components that are configured to load deposition heads 22a-22d to
gantry 18 in an interchangeable manner based on signals provided
from head tool changer (HTC) controller 30.
HTC controller 30 is also one or more computer-operated controllers
for operating head tool changer 12, and may be located internally
or externally to system 10 and/or head tool changer 12. In one
embodiment, the functions of system controller 20 and HTC
controller 30 may be combined into a common computer-operated
controller that may be located internally or externally to system
10 and/or head tool changer 12. Tool rest assembly 26 and actuator
assemblies 28a-28d are discussed in more detail below.
The following discussion of head tool changer 12 illustrates the
use of four interchangeable deposition heads (i.e., deposition
heads 22a-22d). However, head tool changer 12 may be configured to
load additional or fewer numbers of deposition heads to gantry 18.
Examples of suitable numbers of deposition heads for use with head
tool changer 12 range from two to ten, with particularly suitable
numbers ranging from three to six.
FIGS. 2A-2P and 3 are schematic illustrations of a process for
interchangeably loading deposition heads 22a-22d to gantry 18 of
system 10 with the use the head tool changer 12. FIGS. 4-13
subsequently illustrate suitable features of the components
described in FIGS. 2A-2P and 3, pursuant to one embodiment of the
present disclosure. As shown in FIG. 2A, head tool assembly 12 also
includes grip units 34a-34d, tooling units 36a-36d, and master unit
38. Grip units 34a-34d are respectively secured to actuator
assemblies 28a-28d and are configured to engage with and lock to
tooling units 36a-36d. Tooling units 36a-36d are respectively
secured to deposition heads 22a-22d and are configured to engage
with and lock to grip units 34a-34d and master unit 38. Master unit
38 is secured to gantry 18 (e.g., in a carriage of gantry 18) and
is configured to interchangeably engage tooling units 36a-36d.
Accordingly, gantry 18 is configured to move master unit 38 around
in the horizontal x-y plane.
As discussed below, grip units 34a-34d are configured to relay
electrical power and control signals from HTC controller 30 to
tooling units 36a-36d when tooling units 36a-36d are respectively
engaged with grip units 34a-34d. Similarly, master unit 38 is
configured to relay electrical power and control signals from
system controller 20 to one of tooling units 36a-36d when the given
tooling unit is engaged with master unit 38. Tooling units 36a-36d
are also configured to relay the received electrical power and
control signals respectively to deposition heads 22a-22d. As such,
when tooling units 36a-36d are engaged with grip units 34a-34d,
deposition heads 22a-22d receive electrical power and control
signals from HTC controller 30. Alternatively, when one of tooling
units 36a-36d is engaged with master unit 38, the corresponding
deposition head receives electrical power and control signals from
system controller 20.
In the example shown in FIG. 2A, grip units 34a-34d are
respectively engaged with and locked to tooling units 36a-36d,
thereby allowing deposition heads 22a-22d to be operably retained
by actuator assemblies 28a-28d. As such, deposition heads 22a-22d
receive electrical power and control signals from HTC controller 30
via actuator assemblies 28a-28d, grip units 34a-34d, and tooling
units 36a-36d.
Actuator assemblies 28a-28d are each configured to retract and
extend along the vertical z-axis between a raised position and one
or more lowered positions. In particular, as shown in FIG. 2A,
actuator assemblies 28a-28d may extend to a resting position such
that tooling plates 36a-36d rest on tool rest assembly 26. As
discussed above, tool rest assembly 26 is a component on which idle
deposition heads 22a-22d may rest when not loaded to gantry 18, and
may be used for initializing (e.g., warming up and purging) one or
more of deposition heads 22a-22d for use in system 10.
Prior to building a 3D model or support structure, HTC controller
30 may initialize (e.g., warm up and purge) one or more of
deposition heads 22a-22d for use in system 10. For example, HTC
controller 30 may direct head tool changer 12 may to initialize
deposition head 22a at tool rest assembly 26. When deposition head
22a is ready for use, system controller 20 may align gantry 18 such
that master unit 38 is positioned below actuator assembly 28a in
the horizontal x-y plane to receive deposition head 22a, as shown
in FIG. 2A.
As shown in FIG. 2B, HTC controller 30 may then retract actuator
assemblies 28a-28d upward to their raised positions, as indicated
by arrows 40. This desirably positions depositions heads 22a-22d
vertically higher than tool rest assembly 26. As shown in FIG. 2C,
HTC controller 30 may then direct tool rest assembly 26 to slide
along the x-axis in the direction of arrow 42 to avoid obstructing
actuator assemblies 28a-28d.
As shown in FIG. 2D, HTC controller 30 may then extend actuator
assembly 28a downward to an engagement position such that tooling
unit 36a engages master unit 38, as indicated by arrow 44. At this
point, tooling unit 36a may unlock from grip unit 34a and lock to
master unit 38. Additionally, control of deposition head 22a may
transfer from head tool changer 12 and HTC controller 30 to system
10 and system controller 20. In particular, deposition head 22a may
receive electrical power and control signals from system controller
20 respectively via master unit 38 and tooling unit 36a, and the
electrical power and control signals relayed through actuator
assembly 28a, grip unit 34a, and tooling unit 36a may be cut
off.
As shown in FIG. 2E, HTC controller 30 may then retract actuator
assembly 28a to its raised position, as indicated by arrow 46. This
correspondingly disengages grip unit 34a from tooling unit 36a, and
raises grip unit 34a upward into head tool changer 12. As shown in
FIG. 2F, HTC controller 30 may then direct tool rest assembly 26 to
slide back along the x-axis to extend below actuator assemblies
28a-28d, as indicated by arrow 48.
As shown in FIG. 2G, HTC controller 30 may then direct actuator
assemblies 28a-28d to extend to their resting positions such that
tooling units 36b-36d rest on tool rest assembly 26, as indicated
by arrows 50. At this point, system controller 20 may also direct
gantry 18 to move deposition head 22a (and tooling unit 36a and
master unit 38) around in the horizontal x-y plane within build
chamber 14 (shown in FIG. 1), and may direct one or more feed
mechanisms (not shown) to feed a consumable material through
deposition head 22a. The received consumable material is then
deposited onto platform assembly 16 (shown in FIG. 1) to build at
least a portion of a 3D model or support structure using a
layer-based additive technique. After each layer is complete,
platform assembly 16 may be lowered by an increment along the
z-axis to allow successive layers to be formed on top of the
previously deposited layers.
While deposition head 22a is functioning as the active deposition
head, HTC controller 30 may also direct one or more of deposition
heads 22b-22d to be initialized for use in system 10. This allows
the initializations of the deposition heads 22b-22d to be performed
at the same time as deposition head 22a is in use in system 10. For
example, HTC controller 30 may initialize deposition head 22c for
operation after active deposition head 22a has completed its
deposition steps. The timing sequence for initializing deposition
head 22c desirably has deposition head 22c ready for use as soon as
deposition head 22a completes its deposition steps.
In comparison, a deposition head that contains two deposition lines
(e.g., extrusion lines), such as the deposition head disclosed in
Leavitt, U.S. Patent Application Publication No. 2009/0035405,
typically requires the non-active deposition line to be warmed up
and purged between deposition steps. Otherwise, the non-active
deposition line may interfere with the deposition from the active
deposition line (e.g., material may potentially leak from the
non-active deposition line). These the warm up and purge processes
between the deposition steps, however, accumulate over the numerous
layers used to build 3D models and support structures, This can
account for a substantial portion of the overall build time.
Initializing deposition heads 22b-22d in tandem with the operation
of deposition head 22a, however, effectively removes the delays
incurred with warming up and purging non-active deposition lines,
thereby substantially reducing the overall build time.
In addition, an operator of system 10 may inspect, repair, or
otherwise perform work on deposition heads 22b-22d while deposition
head 22a continues to build the 3D model or support structure. As
such, in addition to initializing the non-active deposition heads
(e.g., deposition heads 22b-22d) in tandem with the operation of
the active deposition head (e.g., deposition head 22a), the
non-active deposition heads may also be maintained while inactive,
thereby reducing maintenance delays that may otherwise occur during
operation.
As shown in FIG. 2H, after deposition head 22a completes its
deposition steps, system controller 20 may direct gantry 18 to
position tooling unit 36a and master plate 38 below actuator
assembly 28a in the horizontal x-y plane. HTC controller 30 may
also retract actuator assemblies 28a-28d upward to their raised
positions, as indicated by arrows 52. As discussed above, this
desirably positions depositions heads 22b-22d vertically higher
than tool rest assembly 26. As shown in FIG. 2I, HTC controller 30
may then direct tool rest assembly 26 to slide along the x-axis in
the direction of arrow 54 to again avoid obstructing actuator
assemblies 28a-28d.
As shown in FIG. 2J, HTC controller 30 may then extend actuator
assembly 28a downward to its engagement position, thereby allowing
grip unit 34a to engage with and lock to tooling unit 36a, as
indicated by arrow 56. At this point, tooling unit 36a may unlock
from master unit 38 and lock to grip unit 34a. Additionally,
control of deposition head 22a may now transfer from system 10 and
system controller 20 back to head tool changer 12 and HTC
controller 30. In particular, deposition head 22a may receive
electrical power and control signals from HTC controller 30 via
actuator assembly 28a, grip unit 34a, and tooling unit 36a, and the
electrical power and control signals relayed through master unit 38
and tooling unit 36a may be cut off.
As shown in FIG. 2K, HTC controller 30 may then retract actuator
assembly 28a to its raised position, as indicated by arrow 58. This
correspondingly disengages tooling unit 36a from master unit 38,
and raises grip unit 34a, tooling unit 36a, and deposition head 22a
upward into head tool changer 12. As shown in FIG. 2L, system
controller 20 may then direct gantry 18 to move master unit 38 to
position it below the next actuator assembly to be used (e.g.,
actuator assembly 28c) in the horizontal x-y plane, as indicated by
arrow 60.
As shown in FIG. 2M, HTC controller 30 may then extend actuator
assembly 28c downward to an engagement position such that tooling
unit 36c engages master unit 38, as indicated by arrow 62. At this
point, tooling unit 36c may unlock from grip unit 34c and lock to
master unit 38. Additionally, control of deposition head 22c may
now transfer from head tool changer 12 and HTC controller 30 to
system 10 and system controller 20. In particular, deposition head
22c may receive electrical power and control signals from system
controller 20 respectively via master unit 38 and tooling unit 36c,
and the electrical power and control signals relayed through
actuator assembly 28c, grip unit 34c, and tooling unit 36c may be
cut off.
As shown in FIG. 2N, HTC controller 30 may then retract actuator
assembly 28c to its raised position, as indicated by arrow 64. This
correspondingly disengages tooling unit 36c from grip unit 34a, and
raises grip unit 34c upward into head tool changer 12. As shown in
FIG. 2O, HTC controller 30 may then direct tool rest assembly 26 to
slide back along the x-axis to extend below actuator assemblies
28a-28d, as indicated by arrow 66.
As shown in FIG. 2P, HTC controller 30 may then direct actuator
assemblies 28a-28d to extend downward to their resting positions
such that tooling units 36a, 36b, and 36d rest on tool rest
assembly 26, as indicated by arrows 68. At this point, system
controller 12 may also direct gantry 18 to move deposition head 22c
(and tooling unit 36c and master unit 38) around in the horizontal
x-y plane within build chamber 14 (shown in FIG. 1). This allows
deposition head 22c to deposit a consumable material to build an
additional portion of a 3D model or support structure using the
layer-based additive technique.
This process may then be repeated in a variety of patterns for
building the 3D model and support structure with the materials from
one or more of deposition heads 22a-22d. As discussed above,
initializing the idle deposition heads with head tool changer 12 in
tandem with the operation of the active deposition head may
substantially reduce the overall build time. Additionally, the
interchangeability of deposition heads 22a-22d allows deposition
heads 22a-22d to each include a single deposition line (e.g., a
single extrusion line). This precludes the need for a second,
non-active deposition line, which may otherwise interfere with the
deposition from the active deposition line (e.g., material
leakage).
Furthermore, the interchangeability of deposition heads 22a-22d
allows different materials to be deposited from deposition heads
22a-22d. This allows the 3D model and/or support structure to each
be built with multiple materials having different physical,
chemical, and/or aesthetic properties. For example, deposition head
22a may deposit an acrylonitrile-butadiene-styrene (ABS) modeling
material that is black in color, deposition head 22b may deposit an
ABS modeling material that is red in color, deposition head 22c may
deposit an ABS-polycarbonate modeling material that is blue in
color, and deposition head 22d may deposit a support material for
building a corresponding support structure. Building 3D models from
multiple materials may increase the functional and aesthetic
properties of the given 3D models compared to a 3D model built from
a single material.
Moreover, deposition heads 22a-22d may exhibit different build
parameters. For example, one or more of deposition heads 22a-22d
may be a jetting head while others are extrusion heads.
Additionally, deposition heads 22a-22d may operate at different
extrusion temperatures for use with different consumable materials
and/or may have different extrusion tip sizes. These different
parameters may be desirable in many applications and they increase
the design ranges of 3D models and support structures that may be
built with system 10.
FIG. 3 is a schematic illustration of the engagements between grip
unit 34a, tooling unit 36a, and master unit 38, which corresponds
to the examples shown in FIGS. 2D and 2J, where actuator assembly
28a is extended downward to its engagement position. The following
discussion of deposition head 22a, grip unit 34a, tooling unit 36a,
and master unit 38 may also apply to each additional actuator
assembly of head tool changer 12 (e.g., actuator assemblies
28b-28d) in the same manner.
As shown in FIG. 3, when engaged together, grip unit 34a and
tooling unit 36a define power line 70, which is one or more
conductive lines configured to receive electrical power from head
tool changer 12 (via one or more external power lines), and to
relay the electrical power to deposition head 22a. Additionally,
grip unit 34a and tooling unit 36a define signal line 72, which is
one or more data communication lines configured to receive control
signals from HTC controller 30 (via one or more external signal
lines), and to relay the control signals to deposition head
22a.
Similarly, when engaged together, master unit 38 and tooling unit
36a define power line 74, which is one or more conductive lines
configured to receive electrical power from system 10 (via one or
more external power lines), and to relay the electrical power to
deposition head 22a. Additionally, master unit 38 and tooling unit
36a define signal line 76, which is one or more data communication
lines configured to receive control signals from system controller
20 (via one or more external signal lines), and to relay the
control signals to deposition head 22a.
Deposition head 22a is secured to tooling unit 36a, which allows
deposition head 22a to receive electrical power from either power
line 70 or power line 72, and to receive control signals from
either signal line 72 or signal line 74, depending on whether head
tool changer 12 or system 10 is selected as the controlling system.
The transfer of which system controls deposition head 22a may be
made when tooling unit 36a is engaged with grip unit 34a and with
master unit 38.
In one embodiment, the direction of the transfer of control may be
determined based on the sequence of operation and the previous
state of control. For example, while actuator assembly 28a is
loading tooling unit 36a and deposition head 22a to gantry 18
(e.g., as shown in FIG. 2D), HTC controller 30 has initial control
over deposition head 22a. As such, when tooling unit 36a engages
master unit 38, control may transfer from HTC controller 30 to
system controller 20. Alternatively, while actuator assembly 28a is
removing tooling unit 36a and deposition head 22a from gantry 18
(e.g., as shown in FIG. 2J), system controller 20 has initial
control over deposition head 22a. As such, when grip unit 34a
engages tooling unit 36a, control may transfer from system
controller 20 to HTC controller 30. System controller 20 and HTC
controller 30 may also communicate with each other to initiate the
transfers of control.
Providing electrical power and control signals to deposition head
22a while retained in head tool changer 12 is desirable for
initializing deposition head 22a in tandem with the operation of
another deposition head in gantry 18. As discussed above, this can
substantially reduce the overall build time. Otherwise, if the idle
deposition heads only received electrical power and signal controls
while loaded to gantry 18, the non-active deposition heads would
need to be loaded to gantry 18 before they could be initialized.
This would effectively eliminate the benefits of head tool changer
12 for reducing overall build times.
As further shown in FIG. 3, the engagement between grip unit 34a
and tooling unit 36a also defines locking mechanism 78, which is a
first mechanism for locking tooling unit 36a to grip unit 34a.
Locking mechanism 78 may function in a variety of manners, such as
electromechanical or pressure-based (e.g., pneumatic or hydraulic)
locks. Accordingly, when engaged together, grip unit 34a and
tooling unit 36a define conduit 80, which may be one or more power
lines for supplying electrical power to locking mechanism 78 (for
electromechanical locks) or one or more fluid lines for providing
and expelling pressurized fluids to and from locking mechanism 78
(for pneumatic or hydraulic locks).
Similarly, the engagement between tooling unit 36a and master unit
38 defines locking mechanism 82, which is a second mechanism for
locking tooling unit 36a to master unit 38. Locking mechanism 82
may also function in a variety of manners, such as
electromechanical or pressure-based (e.g., pneumatic or hydraulic)
locks. Accordingly, when engaged together, master unit 38 and
tooling unit 36a define conduit 84, which may be one or more power
lines for supplying electrical power to locking mechanism 82 (for
electromechanical locks) or one or more fluid lines for providing
and expelling pressurized fluids to and from locking mechanism 82
(for pneumatic or hydraulic locks).
For example, while actuator assembly 28a loads tooling unit 36a and
deposition head 22a to gantry 18 (e.g., as shown in FIG. 2D),
tooling unit 36a is initially locked to grip unit 34a (i.e.,
locking mechanism 78 is activated). As such, when tooling unit 36a
engages master unit 38, in addition to transferring the control of
deposition head 22a from HTC controller 30 to system controller 20,
locking mechanism 78 may deactivate and locking mechanism 82 may
activate, thereby locking tooling unit 36a to master unit 38.
Alternatively, while actuator assembly 28a is removing tooling unit
36a and deposition head 22a from gantry 18 (e.g., as shown in FIG.
2J), tooling unit 36a is initially locked to master unit 38 (i.e.,
locking mechanism 82 is activated). As such, when grip unit 34a
engages tooling unit 36a, in addition to transferring the control
of deposition head 22a from system controller 20 back to HTC
controller 30, locking mechanism 82 may deactivate and locking
mechanism 78 may activate, thereby locking tooling unit 36a to grip
unit 34a. This locking arrangement provides an efficient manner for
interchangeably retaining tooling unit 36a (and deposition head
22a) with either grip unit 34a or master unit 38.
As discussed above, FIGS. 4-13 illustrate suitable features of the
components described in FIGS. 2A-2P and 3, pursuant to one
embodiment of the present disclosure. For ease of discussion, the
components of head tool changer 12 discussed in FIGS. 4-13 are
described with the same reference labels as those used for the
components discussed in FIGS. 2A-2P and 3.
FIGS. 4 and 5 are expanded front and rear perspective views of tool
rest assembly 26 and actuator assemblies 28a-28d of head tool
changer 12. As shown in FIG. 4, tool head changer 12 also includes
cross plates 86 and 88, and retention member 90, each of which are
desirably secured to a frame structure of head tool changer 12 (not
shown). Tool rest assembly 26 may be secured to the frame structure
with cross plate 86, thereby positioning tool rest assembly 26 at a
bottom front location of head tool changer 12 in the shown
embodiment. Similarly, actuator assemblies 28a-28d may each be
secured to the frame structure with cross plate 88, thereby
allowing actuator assemblies 28a-28d to be suspended over gantry 18
(shown in FIG. 1) and tool rest assembly 26. Retention member 90 is
an additional plate configured to restrict lateral movement of
actuator assemblies 28a-28d along the y-axis.
As further shown, tool rest assembly 26 includes tool rests
92a-92d, air circulators 94a-94d, and purge receptacle 96, where
air circulators 94a-94d may be secured to cross plate 86. As
discussed below, tool rests 92a-92d and purge receptacle 96 are
desirably slidable relative to cross plate 86 to slide along the
x-axis, as discussed above.
Actuator assemblies 28a-28d respectively include actuator arms
98a-98d and guide rails 100a-100d, where the bottom ends of
actuator arms 98a-98d are respectively secured to cross plate 88
with mounting brackets 102a-102d. The top ends of actuator arms
98a-98d are respectively connected to the top ends of guide rails
100a-100d, thereby allowing the retraction and extension of
actuator arms 98a-98d to respectively move guide rails 100a-100d
upward and downward between the raised position and one or more
lowered positions (e.g., the resting and engagement positions).
As shown in FIG. 5, tool rest assembly 26 also includes slide track
104 and mounting plate 106, where mounting plate 106 is configured
to move back and forth along the x-axis on slide track 104. HTC
controller 30 may move mounting plate 106 with the use of a variety
of drive mechanisms, such as pneumatic drives, hydraulic drives,
and electrochemical motor drives. Tool rests 92a-92d are secured to
mounting plate 106, and purge receptacle 96 is desirably secured to
tool rests 92a-92d. This arrangement allows tool rests 92a-92d to
slide along the x-axis, as discussed above, to avoid obstructing
the lowering of actuator assemblies 28a-28d to their engagement
positions. The use of tool rests 92a-92d and purge receptacle 96
for initializing deposition heads 22a-22d is further discussed
below.
Actuator assemblies 28a-28d also respectively include sleeve
brackets 108a-108d, which are secured to cross plate 88. Guide
rails 100a-100d respectively extend through sleeve brackets
108a-108d, thereby restricting the movement of guide rails
100a-100d to upward and downward directions along the vertical
z-axis.
The following discussion in FIGS. 6-13 is directed to deposition
head 22a, actuator assembly 28a, grip unit 34a, and tooling unit
36a. However, the discussion may also apply to deposition heads
22b-22d, actuator assemblies 28b-28d, grip units 34b-34d, and
tooling units 36b-36d in the same manner. FIGS. 6 and 7 are
opposing side perspective views of grip unit 34a and tooling unit
36a operably connecting guide rail 100a and deposition head
22a.
As shown in FIG. 6, grip unit 34a includes base component 110,
compensator 112, leads 114a and 114b, and couplings 116. Base
component 110 is the portion of grip unit 34a that engages with and
is lockable to tooling unit 36a with locking mechanism 78 (shown in
FIG. 3). In the shown embodiment, base component 110 is fabricated
from multiple sub-blocks that are secured together with fasteners.
In an alternative embodiment, base component 110 may be fabricated
as an integral block. Compensator 112 is secured to the top surface
of base component 110, and is the portion of grip unit 34a that is
secured to the bottom end of guide rail 102a. As discussed below,
compensator 112 allows tooling unit 36a to float laterally and
vertically when engaging tooling unit 36a with master unit 38.
Leads 114a and 114b are electrical connections secured to base
component 110, and are configured to be connected to external
cables (not shown) to receive electrical power and control signals
from head tool changer 12 and HTC controller 30, as discussed above
for power line 70 and signal line 72 (shown in FIG. 3).
Couplings 116 are gas couplings secured to base component 110, and
are configured to be connected to external fluid conduits (not
shown) to receive and expel pressurized gases to operate locking
mechanism 78, as discussed above for conduit 80 (shown in FIG. 3).
Accordingly, in this embodiment, locking mechanism 78 may function
as a pneumatic locking mechanism. In one embodiment, the external
fluid conduits for supplying and recycling the pressurized gases
may also extend along or within actuator arm 98a and guide rail
100a to connect with couplings 116.
Tooling unit 36a includes base component 118, which is secured to
deposition head 22a and is the portion of tooling unit 36a that
engages with and is lockable to base component 110 of grip unit 34a
with locking mechanism 78. In the shown embodiment, base component
118 is also fabricated from multiple sub-blocks that are secured
together with fasteners. In an alternative embodiment, base
component 118 may be fabricated as an integral block.
As further shown in FIG. 6, actuator assembly 28a also includes
electrical connections 120 adjacent to mounting bracket 102a, where
electrical connections 120 are configured to receive electrical
power and control signals from head tool changer 12 and HTC
controller 30 via one or more external electrical cables (not
shown). This allows HTC controller 30 to direct the operation of
actuator assembly 28a for raising and lowering guide rail 100a
along the vertical z-axis. In addition, one or more cables (not
shown) may also extend along or within actuator arm 98a and guide
rail 100a, thereby relaying the electrical power and control
signals from electrical connections 120 to leads 114a and 114b of
grip unit 34a.
In the shown embodiment, deposition head 22a includes control board
122, drive mechanism 124, thermal block 126, and extrusion tip 128,
which may form a single extrusion line, such as a single extrusion
line of the extrusion head described in Leavitt, U.S. Patent
Application Publication No. 2009/0035405. Drive mechanism 124 may
receive a filament of a consumable material from one or more supply
sources retained in bays 19 (shown in FIG. 1) through guide tube
130.
As shown in FIG. 7, deposition head 22a also include bracket 132.
Bracket 132 is a frame component of deposition head 22a and may
retain control board 122, drive mechanism 124, and thermal block
126. Bracket 132 is also the portion of deposition head 22a that
may be secured to base component 118 of tooling unit 36a.
FIG. 8 is a front perspective view of tooling unit 36a and
deposition head 22a engaged with master unit 38. As shown, control
board 122 of deposition head 22a includes power connection ports
134a and 134b, and signal connection ports 135a and 135b, which are
configured to receive electrical power and control signals from
tooling unit 36a via external cables (not shown). For example,
power connection port 134a and signal connection port 135a are
configured to receive electrical power and control signals from
grip unit 34a and tooling unit 36a, as discussed above for power
line 70 and signal line 72 (shown in FIG. 3). Correspondingly,
power connection port 134b and signal connection port 135b are
configured to receive electrical power and control signals from
master unit 38 and tooling unit 36a, as discussed above for power
line 74 and signal line 76 (shown in FIG. 3).
Tooling unit 36a also includes electrical contacts 136a and 136b,
lock ring 138, guide holes 140, and top surface 142, where top
surface 142 is the surface of base component 118 that engages with
grip unit 34a. Electrical contacts 136a and 136b are conductive
contacts located at top surface 142, and are configured to engage
with reciprocating electrical contacts (not shown in FIG. 8)
located at a bottom surface of grip unit 34a. This allows the
electrical power and control signals that are received through
leads 114a and 114b of grip unit 34a (shown in FIGS. 6 and 7) to be
relayed to tooling unit 36a, as discussed above.
Lock ring 138 is a female portion of locking mechanism 78 (shown in
FIG. 3) disposed in base component 118 at top surface 142. Lock
ring 138 is configured to receive a reciprocating male portion of
locking mechanism 78 retained by grip unit 34a for locking tooling
unit 36a to grip unit 34a.
Guide holes 140 are a pair of holes extending within base component
118 at top surface 142, and are configured to receive guide pins
(not shown in FIG. 8) extending from the bottom surface of grip
unit 34a. This arrangement allows the guide pins to align with
guide holes 140 when grip unit 34a and tooling unit 36a engage each
other.
As further shown in FIG. 8, master unit 38 includes base component
144, leads 146a and 146b, and couplings 148. Base component 144 is
the portion of master unit 38 that engages with and is lockable to
the bottom surface of tooling unit 36a with locking mechanism 82
(shown in FIG. 3). Base component 144 is also the portion that may
be secured to a carriage of gantry 18, such as in an adjustable
head mount as disclosed in Comb et al., U.S. Publication No.
2010/0100222. In the shown embodiment, base component 144 is also
fabricated from multiple sub-blocks that are secured together with
fasteners. In an alternative embodiment, base component 144 may be
fabricated as an integral block.
Leads 146a and 146b are electrical connections secured to base
component 144, and are configured to be connected to external
cables (not shown) to receive electrical power and control signals
from system 10 and system controller 20, as discussed above for
power line 74 and signal line 76 (shown in FIG. 3). Couplings 148
are gas couplings secured to base component 144, and are configured
to be connected to external fluid conduits (not shown) to receive
and expel pressurized gases to operate locking mechanism 82, as
discussed above for conduit 84 (shown in FIG. 3). Accordingly, in
this embodiment, locking mechanism 82 may also function as a
pneumatic locking mechanism.
FIGS. 9A and 9B are respectively top and bottom perspective views
of grip unit 34a. As shown in FIG. 9A, compensator 112 includes top
surface 150, springs 152, and electrical ports 154, and is
configured to switch between an unlocked state and a locked state
based on signals received through electrical ports 154. Top surface
150 is the portion of compensator 112 that may be secured to the
bottom end of guide rail 100a (shown in FIGS. 4-7). While in the
unlocked state, springs 152 allow grip unit 34a (and tooling unit
36a when engaged with grip unit 34a) to float laterally and
vertically. This correspondingly provides grip unit 34a a small
freedom of movement when actuator assembly 28a is aligning with
master unit 38. As such, when deposition head 22a is being loaded
to gantry 18, compensator 112 is desirably set to the unlocked
state while grip unit 34a and tooling unit 36a align and engage
with master unit 38. When tooling unit 36a engages with master unit
38, compensator 112 may then be locked to prevent further lateral
or vertical floating.
As shown in FIG. 9B, grip unit 34a further includes bottom surface
156, electrical contacts 158a and 158b, lock extension 160, and
guide pins 162. Bottom surface 156 is the surface of grip unit 34a
that may engage with top surface 142 of tooling unit 36a (shown in
FIG. 8). Electrical contacts 158 and 158b are conductive contacts
located at bottom surface 156, and are configured to engage with
electrical contacts 136a and 136b (shown in FIG. 8) of tooling unit
36a.
Lock extension 160 is a male portion of locking mechanism 78 (shown
in FIG. 3) extending from bottom surface 156, and is configured to
extend into lock ring 138 of tooling unit 36a for locking grip unit
34a to tooling unit 36a. In the shown embodiment, lock extension
160 includes a plurality of plugs that are capable of expanding
outward and contracting inward from lock extension 160 based on the
pressure within lock extension 160. As a result, lock extension 160
may be secured to lock ring 138 by introducing pressurized gas
through couplings 116, which cause the plugs to expand outward to
physically trap lock extension 160 in lock ring 138. Guide pins 162
are a pair of pins extending downward from bottom surface 156, and
are configured to engage guide holes 140 of tooling unit 36a, as
discussed above.
FIGS. 10A and 10B are respectively top and bottom perspective views
of tooling unit 36a. As shown in FIG. 10A, tooling unit 36a also
includes lateral surface 164, power connection ports 166a and 166b,
and signal connection ports 168a and 168b. Lateral surface 164 is
the surface of tooling unit 36a that may be secured to bracket 132
of deposition head 22a to secure deposition head 22a to tooling
unit 36a. Power connection ports 166a and 166b, and signal
connection ports 168a and 168b are configured to relay electrical
power and control signals from tooling unit 36a respectively to
power connection ports 134a and 134b and signal connection ports
135a and 135b of deposition head 22a, via external cables (not
shown). As discussed above, this arrangement allows deposition head
22a to receive electrical power and control signals from power line
70 and signal line 72 (shown in FIG. 3) that are relayed through
grip unit 34a and tooling unit 36a, and from power line 74 and
signal line 76 (shown in FIG. 3) that are relayed through master
unit 38 and tooling unit 36a.
As shown in FIG. 10B, tooling unit 36a further includes bottom
surface 170, electrical contacts 172a and 172b, lock ring 174,
guide holes 176, and mating guides 178. Bottom surface 170 is the
surface of tooling unit 36a that may engage with master unit 38.
Electrical contacts 172a and 172b are conductive contacts secured
to base component 118, and are configured to engage with
reciprocating electrical contacts of master unit 38 (not shown in
FIG. 10B).
Lock ring 174 is a female portion of locking mechanism 82 (shown in
FIG. 3) disposed in bottom surface 170, and is configured to
receive a lock extension of master unit 38 (not shown in FIG. 10B).
Guide holes 176 are a pair of holes extending within bottom surface
170 and are configured to receive guide pins of master unit 38 (not
shown in FIG. 10B). Mating guides 178 are a plurality of guides
configured to receive domes (not shown in FIG. 10B) of master unit
38. As discussed below, the engagement between the domes and mating
guides 178 provide a precision mating mechanism for tooling unit
36a and master unit 38.
FIGS. 11A and 11B are respectively top and bottom perspective views
of master unit 38. As shown, master unit 38 also includes top
surface 180, electrical contacts 182a and 182b, lock extension 184,
guide pins 186, and domes 188. Top surface 180 is the surface of
master unit 38 that may engage with bottom surface 170 of tooling
unit 36a. Electrical contacts 182a and 182b are conductive contacts
located at top surface 180, are configured to engage with
electrical contacts 172a and 172b of tooling unit 36a. This allows
the electrical power and control signals that are received through
leads 146a and 146b to be relayed to tooling unit 36a, as discussed
above.
Lock extension 184 is a male portion of locking mechanism 82 (shown
in FIG. 3) extending from top surface 180, and may function in the
same manner as lock extension 160 (shown in FIG. 9B). Accordingly,
lock extension 184 is configured to extend into lock ring 174 of
tooling unit 36a, thereby allowing master unit 38 to lock to
tooling unit 36a based on the pressurized gases received via
couplings 148. Guide pins 186 are a pair of pins extending upward
from top surface 180, and are configured to engage guide holes 176
located bottom surface 170 of tooling unit 36a. This arrangement
allows guide pins 186 to align with guide holes 176 when tooling
unit 36a and master unit 38 engage each other.
Domes 188 are a plurality of topographical features (e.g., half
spheres) extending above the plane of top surface 180 and are
configured to engage with mating guides 178 to provide a precision
mating mechanism. In the shown embodiment in which master unit 38
includes three domes 188 and tooling unit 36a includes three mating
guides 178, this precision mating provides six degrees of
restraint. This restraint defines a rigid body that resists lateral
movement of tooling unit 36a relative to master unit 38 in the
horizontal x-y plane when tooling unit 36a is locked to master unit
38. This is desirable to allow gantry 18 to prevent tooling unit
36a and deposition head 22a from moving laterally relative to
master unit 38 during operation in system 10.
FIGS. 12A and 12B are respectively top and bottom exploded
perspective views of grip unit 34a, tooling unit 36a, and master
unit 38, which illustrate their respective engagements with each
other. For example, when grip unit 34a is lowered onto tooling unit
36a to retract tooling unit 36a from master unit 38 (e.g., as shown
in FIG. 2J), guide pins 162 may enter guide holes 140 to align grip
unit 34a with tooling unit 36a, and lock extension 160 may enter
lock ring 138. The lateral freedom attained with compensator 112 in
the unlocked state reduces the risk of damage to grip unit 34a and
tooling unit 36a during the alignment.
When grip unit 36a engages tooling unit 36a, electrical contacts
158a and 158b of grip unit 34a engage with electrical contacts 136a
and 136b of tooling unit 36a, thereby allowing electrical power and
control signals to be relayed from leads 114a and 114b of grip unit
34a to electrical contacts 166a and 168a of tooling unit 36a. Head
tool changer 12 may then introduce pressurized gas into couplings
116 to engage lock extension 160 within lock ring 138 to lock
tooling unit 36a to grip unit 34a. Additionally, compensator 112
may be locked to restrict lateral movement.
System 10 may also release the pressurized gas from couplings 148
to unlock lock extension 184 from lock ring 174, thereby unlocking
tooling unit 36a from master unit 38. Additionally, transfer of
electrical power and signal control of deposition head 22a to HTC
controller 30 may also occur after electrical contacts 158a and
158b engage with electrical contacts 136a and 136b. Actuator
assembly 28a may then raise grip unit 34a to disengage tooling unit
36a from master unit 38, as discussed above.
Alternatively, when grip unit 34a and tooling unit 36a are lowered
onto master unit 38 (e.g., as shown in FIG. 2D), guide pins 186 may
enter guide holes 176 to align tooling unit 36a with master unit
38, and lock extension 184 may enter lock ring 174. The lateral
freedom attained with compensator 112 in the unlocked state also
reduces the risk of damage to tooling unit 36a and master unit 38
during this alignment.
When tooling unit 36a engages master unit 38, electrical contacts
172a and 172b of tool unit 36a engage with electrical contacts 182a
and 182b of master unit 38, thereby allowing electrical power and
control signals to be relayed from leads 144a and 144b of master
unit 38 to electrical contacts 166b and 168b of tooling unit 36a.
Head tool changer 12 may then introduce pressurized gas into
couplings 148 to engage lock extension 184 within lock ring 174 to
lock tooling unit 36a to master unit 38. Additionally, compensator
112 may be locked to restrict lateral movement.
Head tool changer 12 may also release the pressurized gas from
couplings 116 to unlock lock extension 160 from lock ring 138,
thereby unlocking grip unit 34a from tooling unit 36a.
Additionally, transfer of electrical power and signal control of
deposition head 22a to system controller 20 may also occur after
electrical contacts 172a and 172b engage with electrical contacts
182a and 182b. Actuator assembly 28a may then raise grip unit 34a
disengage grip unit from tooling unit 36a, as discussed above.
FIG. 13 is a rear perspective view of a portion of tool rest
assembly 26 in use with deposition head 22a retained by actuator
assembly 28a, where deposition head 22a may be retained at tool
rest 92a when not loaded to gantry 18, as discussed above in FIG.
2P. As shown in FIG. 13, tool rest 92a includes tool mount 190,
purge trap 192, and purge line 194. Tool mount 190 extends above
purge trap 192 and includes top surface 196 and guide pins 198. Top
surface 196 is the surface of tool rest 92a that may engage with
bottom surface 170 of tooling unit 36a. Furthermore, guide pins 198
are configured to engage with guide holes 176 of tooling unit 36a,
thereby aligning deposition head 22a into purge trap 192.
When tooling unit 36a rests on top surface 196 of tool mount 190, a
portion of thermal block 126 and extrusion tip 128 extend into
purge trap 192. Purge trap 192 is a secondary trap for collecting
any excess purge material that does not travel into purge line 194.
Purge line 194 interconnects purge trap 192 and purge receptacle 96
(shown in FIGS. 4 and 5) for directing purge material to purge
receptacle 96. In one embodiment, purge receptacle 96 may be
connected to a vacuum line (not shown) to actively draw purge
materials through purge line 194 into purge receptacle 96. In an
alternative embodiment, purge receptacle 96 may be omitted and
purge line 194 may be directly connected to a vacuum line.
During an initialization process to warm up and purge deposition
head 22a, deposition head 22a desirably rests on tool rest 92a. HTC
controller 30 (shown in FIG. 1) may then power up deposition head
22a and heat up thermal block 126 to an operating temperature. HTC
controller 30 may the direct drive mechanism 124 to feed successive
portions of a consumable material to thermal block 126. The
consumable material may then melt in thermal block 126 and deposit
from extrusion tip 128 for a preset purge period.
During the purge operation, air circulator 94a also desirably
directs cooling air to drive mechanism 124 and/or the entrance of
thermal block 126 to prevent the consumable material from melting
at the entrance of thermal block 126. Gantry 18 (shown in FIG. 1)
may also include an additional cooling manifold (not shown) for use
with a deposition head in system 10. However, air circulators
94a-94d allow the non-active deposition heads 22a-22d to also
receive cooling air to prevent premature melting of the consumable
materials during purge operations.
FIG. 14 is a schematic illustration of head tool changer 212, which
is an example of an alternative head tool changer of the present
disclosure for use with system 10. Head tool changer 212 functions
in a similar manner as head tool changer 12, and the corresponding
reference labels are increased by "200". As shown, head tool
changer 212 includes a single actuator assembly 228 and a single
grip unit 234 rather than multiple actuator assemblies and grip
units. Accordingly, HTC controller 30 is further configured to
slide tool rest assembly 226 along the x-axis to position tooling
units 236a-236d below grip unit 234 in the horizontal x-y plane,
thereby allowing actuator assembly 226 and grip unit 234 to
selectively retain tooling units 236a-236d and deposition heads
22a-22d in an interchangeable manner for loading and uploading to
and from master unit 238.
In one embodiment, the tool rests of actuator assembly 226 may each
provide electrical power and control signals to deposition heads
22a-22d while tooling units 236a-236d rest on the tool rests of
actuator assembly 226. In this embodiment, HTC control 230 may also
be connected to the tool rests of actuator assembly 226 to relay
electrical power and control signals to tooling units 236a-236d and
deposition heads 22a-22d. This arrangement allows one or more
deposition heads 22a-22d to be warmed up while disengaged from
actuator assembly 228. Examples of suitable electrical connections
include those discussed above for master units 38, 138, and 238,
thereby allowing deposition heads 22a-22d to be powered and
controlled from connections located below tooling units
236a-236d.
Accordingly, during operation, tool rest assembly 226 may slide
along the x-axis to position one of tooling units 236a-236d below
grip unit 234, and actuator assembly 228 may then extend downward
to engage and lock grip unit 234 to the given tooling unit.
Actuator assembly 228 may then retract to its raised position, tool
rest assembly 226 may then slide out of the way (e.g., as shown
above in FIG. 2C), and actuator assembly 228 may then extend
downward to its engagement position to engage the given tooling
unit with master unit 238, as discussed above. This process
discussed above in FIGS. 2A-2P may then be applied to selectively
load tooling units 236a-236d and deposition heads 22a-22d to master
unit 238 and gantry 18 in an interchangeable manner.
In an alternative embodiment, actuator assembly 228 may also be
movable along the x-axis to selectively position grip unit 234 over
tooling units 236a-236d. Accordingly, the tool head changers of the
present disclosure (e.g., head tool changers 12 and 212) may
include at least one actuator assembly and at least one grip unit
for loading deposition heads to gantry 18 of system 10.
Furthermore, in one embodiment, deposition heads may be supplied to
head tool changers 12 and 212 in magazines, turrets, and other
similar carrier units. For example, tool rest assemblies 26 and 226
may each be loadable and unloadable to and from head tool changers
12 and 212 This arrangement allows different deposition heads to be
supplied to head tool changer 212. When each supply of deposition
heads is provided to head tool changer 212 or 212, the given system
may then perform a calibration routine to align grip units 34a-34d
and 234 with the corresponding tooling units 36a-36d and 236a-236d.
The supplied deposition heads may then undergo initializations and
may be loaded to gantry 18 in an interchangeable manner, as
discussed above. This increases the versatility of the head tool
changers in providing multiple deposition heads to system 10.
Although the present disclosure has been described with reference
to preferred embodiments, workers skilled in the art will recognize
that changes may be made in form and detail without departing from
the spirit and scope of the disclosure.
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